This application claims the priority of the German patent applications 197 04 904 4, 197 22 218 8 and 197 33 712.0, filed on Feb. 10, 1997, May 28, 1997 and Aug. 4, 1997, and the disclosure of which is incorporated herein by reference in its entirety.
The invention relates to a rubber-dam and a method according to the preamble of the independent claims.
In dentistry, a rubber-dam is an aid for dental treatments that allows an isolation and thereby to keep the teeth to be treated dry. By this isolation the danger of infection in the area of the treated tooth is reduced as well. Synonymous terms are rubber dam, stretching rubber (Spanngummi), rubber flap (Gummilappen), rubber plate (Gummiplatte), rubber cloth (Gummituch), etc.
Since the year 1864 it has been known to puncture a rubber cloth and to pull it over the tooth such that the edge of the hole in the rubber cloth abuts on the hard tooth and the rubber cloth covers the oral mucosa while the upper part of the tooth remains treatable. For better attaching the rubber.foil to the teeth various means have been proposed. Most widely propagated are, however, metal clamps that affix the rubber cloth to the tooth.
Even though the rubber-dam could be of largest significance for modern dental treatments, it is only seldom used by dentists.
Hence, it is a task of the invention to further develop a rubber-dam and the method according to the preamble, which lives up to the grown requirements of the dental practice.
In one aspect of the invention, this task is solved by the rubber-dam. The cover means hence is substantially bag-shaped, i.e. it is pre-shaped like a bag. In contrast to known embodiments, where the cover means is formed by a planar-foil, the rubber-dam according to the invention can be mounted in the oral cavity without strong deformation. Thereby, the application is made easier and lower retaining forces are required for affixing.
For sealing the rubber-dam against the hard dental material, soft tissue or affixing devices it can be provided with adhesive areas.
Since affixing the rubber-dam requires small retaining forces only, affixing is made easier and conventional attaching clamps, which can damage the teeth, are not required. Instead of this, it becomes possible to uncover not only the teeth but also the gingiva in the working area, such that the neck of the tooth and the adjacent gingiva become accessible for treatment by the dentist. This is of central importance for modern dental treatment.
It is advantageous to use a holder means, by means of which the cover means can be pushed against the oral cavity. This improves sealing and results in even lower forces in a possible adhesive area.
In another aspect of the invention the rubber-dam comprises a cover means and an affixing device, wherein the affixing device comprises a holder means that is firmer than the cover means and connected to the cover means and which can be set against the gingiva on both sides of the dental row in the oral cavity, for commonly isolating tooth and gingiva. In this case, the cover means does not necessarily have to be bag shaped in its relaxed state.
This embodiment of the invention is based on the finding that the conventional rubber-dam affixed to the tooth necessarily covers a lower area of the teeth and therefore substantially limits the dry working field. Treatments in the area of the gingival margin are hardly possible or only under traumatization of the marginal sulcus. Treatments that involve the gingiva cannot be carried out with the known rubber-dam at all. The rubber-dam according to the invention, however, allows to maintain the tooth neck and the adjacent gingiva as an inseparable unit of treatment for the dentist and to isolate a dento-gingival unit from the oral cavity.
The affixing device lays the cover means against the gingiva on both sides of the dental row and therefore leaves enough room in the area of the teeth for cutting out an opening, which provides access to the tooth or teeth to be treated as well as the gingiva around them. In the jaw area to be treated, the restoration margin and marginal gingiva are therefore laid open as a treatment unit, wherein the firmer holder means extends around this treatment unit for laying the cover means against the gingiva.
It is advantageous if a gluing or adhesive area, respectively, is arranged in the area of the holder means. If only a retention function is required, this gluing area can be dispensed with. However, in order to reach good protection against infections and humidity, a reversible gluing zone is proposed for attaching the over means in the area of the humid oral cavity. Glues hat have proved to be suited for slightly wetted mucosa re e.g.: Pectin, gelatine, sodium carboxyl cellulose, olyisobutylene, calcium-sodiumalginate, hydrocolloid-compounds, polyvinyl acetate and carboxyl methyl celluose, etc. The gluing area is located preferably at least also on the holder means or on the side of the cover means opposite to the holder means, depending on which side of the cover means the holder means is arranged.
It is especially favorable if the area of the over means lying between the holder members arranged on both sides of the row of teeth is used as gluing area. This area can be positioned against the gingiva without any pressure and the flexibility of the cover means allows a simple adaptation to irregularities in the gingival region.
In order to optimally adapt the holder means to the individual anatomy, it is proposed that the holder means is plastically deformable. The firmness is then chosen such that an adaptation to the individual gingival shape, without pressure to the gingiva, is guaranteed.
The holder means can, however, also be elastic. An anatomically adapted form of the holder means is in this case produced from an elastic material, for being versatile and for exerting a slight pressure to the gingiva without injuring adjacent tissue.
In addition to this, the holder means can comprise plastic and elastic sections at the same time, e.g. for being plastically adaptable against the gingiva parallel to the tooth row and being elastic transversely to the tooth row for holding the plastic sections against the gingiva.
A preferred embodiment provides that the holder means is arranged around an opening in the cover means. In this way, a frame is created that, in practice, surrounds the treated tooth area and lays the cover means against the gingiva.
Since the tooth rows have arc shape, it is proposed that the holder means comprises two concentric arc members arranged at a distance from each other. This allows to place one arc member of the holder means from S within and the other from without the tooth row against the gingiva. U-shaped arc members allow the isolation of the complete upper or lower jaw.
It is further proposed that the holder means comprises two concentric ring members arranged at a distance from each other. These ring members can be introduced into the oral cavity in such a way that they form two U-shaped arc members for uncovering the upper and the lower jaw. In this case it is advantageous if the ring members are separated by buckling points on opposite sides of the ring into U-shaped arc members.
When arc or ring members are used, it is advantageous to provide a gluing area between the arc or ring members, respectively. This gluing area allows a good isolation in the area of the opening in the cover means, as well as an adaptation between holder means and gingiva.
To allow an attachment of the cover means to the tooth row in addition the holder means while avoiding the known, clawed, traumatizing rubber-dam clamps, it is proposed that the affixing device comprises truly and anatomically shaped, non-traumatizing plastic clips that can be pushed over the tooth, either applied directly onto the tooth with the cover means thereon or vice versa, in each case sealed by an adhesive. These clips are adequately soft such that they do not damage the tooth and can also abut on the gingiva. These clips can also be connected to the holder means and stabilize the latter.
Further it is proposed that the rubber-dam according to the invention comprises a rubber-dam frame, which is arranged circularly around the affixing device. A so-called perioral frame stabilizes the cover means on the outside and preferably extends circularly around the upper and lower lip. This rubber-dam frame is preferably adaptable such that it does not disturb the dentist or patient, e.g. by being radially extendible.
In a further preferred embodiment at least one groove is arranged in an incisal/occlusal area of the cover means, which marks the place where the rubber-dam must be cut open in order to gain access to the corresponding teeth. In this way, an accurate opening of the cover means becomes possible.